Homicide during psychotic illness in New South Wales between 1993 and 2002

Abstract

Objective: To review homicides committed during psychotic illness in New South Wales over 10 years from 1993 to 2002.

Design and setting: Case series of all known homicides committed during psychotic illness in NSW, taken from reports of psychiatrists submitted in proceedings in the Supreme Court of NSW.

Main outcome measures: Demographic and clinical features of perpetrators; estimated frequency of homicide during psychotic illness.

Results: In the 10 years from 1993 to 2002, there were at least 88 people charged with 93 homicide offences committed during the acute phase of mental illness. High rates of drug misuse, especially of drugs known to induce psychotic illness and brain injury, were reported. Evolving auditory hallucinations and delusional beliefs that led the person to believe they were in danger were the symptoms strongly associated with lethal assault. The victims were mostly family members or close associates. Only nine of the victims were strangers, including three fellow patients. Most lethal assaults (69%) occurred during the first year of illness, and the first episode of psychotic illness was found to carry the greatest risk of committing homicide.

Conclusions: People in their first episodes of mental illness should be considered to be at greater risk of committing serious violence than those in subsequent episodes. Illicit drug use, a history of brain injury, auditory hallucinations and delusional beliefs of immediate danger were particularly associated with lethal assault.